First, I cannot attach data or a workbook at this time since the data is sensitive (also complicated to make a fake dataset). I know I am breaking the rules and it is hard to fix my problem without the attachments, but I am going to try anyway.

I am having trouble with a LOD calculation for a denominator. I have a spreadsheet with rows, the COUNT of which is the denominator. A certain subset of the rows is the numerator, and I want to calculate a simple rate (num/denom)*100.

I have several filters/variables that need to affect the data. Some (location, date) need to adjust the denominator and numerator. Others (type, level) only need to affect the numerator while the denominator remains consistent.

With various other iterations. All of them return incorrect numbers for the denominator. Moreover, when a numerator value is 0 for a particular time (ex. March 2018), tableau does not seem to include the March denominator in the overall 2018 aggregation, even though the numerator is non-0 for other months, and aggregates just fine.

ANy ideas? I would do this in R in just a few minutes, but due to multiple reasons I cannot link R to this workbook.

Please confirm: numerator is not a LOD express, just a calculation, correct?

You should be able to just do {COUNT([Row ID])} as you've done above, but then right-click on Location and Date in the filters and select 'Add to Context'. This should change the filter to a gray color, but that might just be it. It essentially partitions the data in this sheet. Please let me know if this works! Hard to say without being able to test.

When I did that the COUNT of the denominator with the added context and displayed by the numerator type, it only counts where the numerator is valid.

Ex. I have 1000 rows (denominator), 100 of those 1000 are events (numerator). So rate should be 100/1000... of the total numerator, 60 are type 1 and 40 are type 2. Therefore the rate for type 1 is 60/1000 and the rate for type 2 is 40/1000. What tableau gives me for the denominator (after adding the contexts for date and location) is 100 for the total, 60 for type 1, and 40 for type 2 etc...

I will try to find some time today to fake this data and post it. I know that would be MUCH easier!